2 lbs boneless, skinless chicken breast
black pepper, to taste
1/3 cup low-sodium soy sauce (tamari for gluten-free)
1/4 cup honey
1/4 cup tomato paste
3 tbsp rice wine vinegar
2 cloves garlic, minced
1 tbsp water
1 tsp sesame oil
1 tsp onion powder
1 tsp sriracha hot chili sauce, or more to taste
1 heaping tbsp cornstarch
1/4 cup water
1/2 tbsp sesame seeds
2 medium scallions, chopped for garnish